Reference guide

✔ Standard-stocked product

Continuous cast • GreenAlloys™

Tin bronze alloys such as C90300 are typically found in gear and high-strength bushing and bearing applications where high strength, low speeds, and heavy loads are present. Other high-strength applications for these alloys are pump impellers, piston rings, steam fittings, and valve bodies. C903 tin bronze castings are utilized in movable bridge components, turntables for bridges, and other structures for fixed and expansion bearings with slow or intermittent movement and heavy loads.


Product description: Tin bronze
Solids: 1/2" to 10" O.D.
Tubes: 1" to 16" O.D.*
Rectangles: Up to 20"
Standard lengths: 144"
Shape/Form: Semi-finished, mill stock or near-net shapes, anode, bar stock, billet/bloom, squares, hex, plate, profile or structural shape, flats/rectangular bar

*Consult mill for wall thickness

Typical uses

Building: Heavy construction equipment
Fasteners: Swivel
Industrial: Bearings, bushings, gear blanks, gears, piston rings, pump bodies, pump impellers, valve bodies, valves
Plumbing: Steam fittings

Chemical composition

Cu%1 Pb% Sn% Zn% Fe% P%1,2 Ni% Al% S% Sb% Si%
Chemical composition according to ASTM B505/B505M-23

1In determining Cu min., Cu may be calculated as Cu + Ni.  2Ni value includes Co.
Note: Cu + sum of named elements, 99.4% min. Single values represent maximums.


Copper alloy UNS No. Machinability rating Density (lb/in3 at 68 °F)
C90300 30 0.318

Mechanical properties

Mechanical properties according to ASTM B505/B505M-23
Tensile strength, min Yield strength, at 0.5% extension under load, min Elongation, in 2 in. or 50 mm min Brinell hardness (500 kg load) Remarks
ksi MPa ksi MPa % typical BHN  
44 303 22 152 18 70

Physical properties

Physical properties provided by CDA

  US Customary Metric
Melting point - liquidus 1832 °F 1000 °C
Melting point - solidus 1570 °F 854 °C
Density 0.318 lb/in3 at 68 °F 8.80 gm/cm3 at 20 °C
Specific gravity 8.8 8.8
Electrical conductivity 12% IACS at 68 °F 0.069 MegaSiemens/cm at 20 °C
Thermal conductivity 43.2 Btu/sq ft/ft hr/°F at 68 °F 74.8 W/m at 20 °C
Coefficient of thermal expansion 68-392 10 · 10-6 per °F (68-392 °F) 17.3 · 10-6 per °C (20-200 °C)
Specific heat capacity 0.09 Btu/lb/°F at 68 °F 377.1 J/kg at 20 °C
Modulus of elasticity in tension 14000 ksi 96527 MPa
Magnetic Permeability 1 1

Fabrication properties

Fabrication properties provided by CDA
*Since brazing is performed within the hot-short range, strain must be avoided during brazing and cooling.
Technique Suitability
Soldering Excellent
Brazing* Good
Oxyacetylene welding Fair
Gas shielded arc welding Fair
Coated metal arc welding Fair
Machinability rating 30

Thermal properties

Thermal properties provided by CDA
Temperature is measured in fahrenheit.   **For stress relief, Solution treatment and annealing - time is measured in hours/inch of thickness. For precipitation heat treatment - time is measured in hours.
Treatment Value* Time**
Stress relief 500  
Solution treatment   0

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